Catheters are tubular devices that may be used in the medical field for numerous applications. It is generally desirable to obtain a maximum torsional rigidity while retaining a satisfactory longitudinal flexibility and stiffness without kinking. These features may allow the orientation of the catheter to be manipulated so that the catheter can be guided through small body vessels and cavities. These features may also prevent any kinking, and may provide the catheter with enough “push” or stiffness so as to prevent the catheter from wrinkling or folding back on itself during this process. The specific nature of these characteristics may vary depending on the specific application for which the catheter is being used. It may also be beneficial to provide a relatively small outside diameter and a lumen or an inside diameter as large as possible.
Catheters (with our without guide wires) may be used both as a diagnostic tool and in the treatment of diseases. One such diagnostic procedure is cardiac catheterization which is a widely performed procedure, being used for assessment of coronary artery disease. Other uses are neurologic uses, radiologic uses, electrophysiologic uses, peripheral vascular uses, etc. One example of a treatment use is the use of balloon catheters in dilation procedures to treat coronary disease. Dilation procedures rely upon the use of a catheter for injection of contrast and delivery of guidewires and dilation catheters to the coronary artery or other arteries. An example of the use of guide wires is for Percutaneous Transluminal Coronary Angioplasty (PTCA) balloons and for guiding diagnostic catheters through the arteries and to body organs.
The catheters and guide wires used in these and other procedures must have excellent torque characteristics, and must have the requisite flexibility. In addition, it is important that catheters and guidewires provide sufficient longitudinal support for “pushing” of items through the arteries and other vessels such as when feeding the balloon portion of an angioplasty catheter through the arteries. Unless there is sufficient stiffness, the catheter or guidewire will wrinkle or fold back on itself. Catheters should ideally have sufficient torque such that they do not buckle when being manipulated. Flexibility may be important so that the catheter can be manipulated into the varying arterial branches encountered by the catheter.
Prior art catheters are typically made of flexible materials which are reinforced such that the resulting composite catheter approximates the desired characteristics. In alternative approaches, guide wires are used in conjunction with catheters to assist in manipulating and moving the catheters through the arterial system in the body. Described herein are catheters are highly flexible, while maintaining stability, preventing kickback and resisting prolapse and kinking.